State ONE animal factor that might have influenced the digestibility of the feed above.

The manure contains 40% moisture, meaning 60% is dry matter.

$$\text{Dry matter in manure} = \text{Total manure} \times (100\% - \text{Moisture percentage})$$ $$\text{Dry matter in manure} = 3.5 \text{ kg} \times (1 - 0.40)$$ $$\text{Dry matter in manure} = 3.5 \text{ kg} \times 0.60$$ $$\text{Dry matter in manure} = 2.1 \text{ kg}$$

The dry matter absorbed is the difference between the dry matter consumed and the dry matter excreted.

$$\text{Dry matter absorbed} = \text{Dry matter consumed} - \text{Dry matter in manure}$$ $$\text{Dry matter absorbed} = 12.5 \text{ kg} - 2.1 \text{ kg}$$ $$\text{Dry matter absorbed} = \boxed{\text{10.4 kg}}$$

2.4.2

One animal factor that might have influenced the digestibility of the feed is the age of the animal.